The Operational Core of this CRC is designed: 1) to survey the prevalence and correlates of depression, dementia and other late life mental disorders in the inpatient, long term care, out patient, and community- dwelling populations of the Center; 2) to recruit, assess, diagnose and track those populations; and 3) to serve as consultants to CRC investigators regarding recruitment, assessment, instrument validity and reliability, tracking and diagnosis of subjects. The Operational Core consist of two interacting components: the Assessment, Recruitment, and Tracking (ART) Service and Diagnostic Resources. The ART Services identifies potential research subjects for the CRC, is a resource for consultation on issues of assessment, maintains assessment standards and validity, and is resource for the Core's data acquisition that is conducted by research assistants without formal clinical training (directed by T. Harralson). Diagnostic Resources serves the CRC by providing expertise in psychiatric diagnoses (directed by J. Streim), neuropsychology (directed by R. Gur) and geriatric medicine (directed by J. Johnson). The Psychiatric Diagnosis subcomponent conducts standardized psychiatric assessments and neuropsychological evaluations to ensure that subjects entered into CRC research studies are well characterized. It also serves as consultative resource on clinical geriatric psychiatry and neuropsychology for CRC investigators, and works in conjunctions with the ART service to validate its methods. The Medical subcomponent works with the ART Service to establish and validate standardized methods for using medical records, clinician reports and subject (or proxy) report to characterize the medical status of research subjects both in terms of summary measurement of "medical burden" and disease-specific measures. It also serves as a consultative resource on medical issues, and as a vehicle for obtaining individual medical assessments of CRC subjects.